Method for melting and flaking metallized pellets

Abstract

The invention provides a method for metalized pellet melting flaking, which comprises the following steps: putting a metalized pellet sample, calcium carbonate and sodium peroxide into an oxidation crucible, and mixing to obtain a premix; putting an oxidation crucible filled with the premix into a platinum yellow crucible; the platinum yellow crucible is placed in a high-frequency melting furnace to be oxidized, the oxidation temperature ranges from 600 DEG C to 700 DEG C, and the oxidation time ranges from 120 s to 150 s; and a release agent is added into the platinum yellow crucible, the platinum yellow crucible is continuously put into the high-frequency melting furnace for melting flaking, and the melting flaking time ranges from 1050 s to 1240 s. According to the method, the situation that the platinum yellow crucible is easily corroded when the metallized pellet sample is directly placed in the platinum yellow crucible for melting and flaking can be effectively avoided, meanwhile, the long-time pre-oxidation treatment step of the metal pellet sample is omitted, the melting and flaking time is effectively shortened, and the detection efficiency of the metallized pellet sample is improved.

Description

Technical Field

[0001] The present application relates to the technical field of chemical analysis and detection, and in particular to a method for melting and flaking metallized pellets. Background Art

[0002] Melt-sample X-ray fluorescence (XRF) is a highly mature chemical analysis method for determining the content of various chemical components in oxide raw materials such as ores, refractory materials, and auxiliary materials. It provides accurate results and has been the subject of several national testing standards. However, when this method is applied to the determination of metallized pellet samples, the metal and residual carbon in the pellets, upon contact with platinum at high temperatures, easily alloy with the platinum, severely corroding the platinum crucible. Consequently, the pellet samples cannot be directly demolded from the crucible to produce fused sheets. Prior art solutions to this problem have been disclosed, such as Chinese invention patent application CN118724007A, which discloses a composite flux and a method for X-ray fluorescence detection of 11 elements in ferrosilicon alloys using direct oxidation melt sampling. This patent describes a hemispherical recess in the flux to hold the sample and oxidant, uses lithium carbonate and lithium hydroxide as oxidants, and designs an oxidation melt heating parameter curve to produce fused sheets directly using direct oxidation melt. However, this patent results in a liquid formed during the melting of the sample and oxidant. This liquid flows into the gaps in the composite flux and comes into contact with the platinum crucible, which can easily cause corrosion. Summary of the Invention

[0003] The present application aims to solve the technical problem in the prior art that the metallized pellet sample is directly placed in a platinum crucible for melting and flaking, which easily causes the platinum crucible to be corroded; and proposes a method for melting and flaking of metallized pellets, so as to effectively avoid the situation where the metallized pellet sample is directly placed in a platinum crucible for melting and flaking, which easily causes the platinum crucible to be corroded. At the same time, the long pre-oxidation treatment step of the metal pellet sample is omitted, thereby effectively reducing the melting and flaking time and improving the detection efficiency of the metallized pellet sample.

[0004] In order to achieve the above-mentioned purpose, this application adopts the following technical solutions:

[0005] A method for melt-slicing metallized pellets, comprising the following steps:

[0006] The metallized pellet sample, calcium carbonate and sodium peroxide are placed in an oxidation crucible and mixed to obtain a premix;

[0007] Place the oxidized crucible containing the premix into the platinum crucible;

[0008] Then, the platinum crucible is placed in a high-frequency melting furnace for oxidation, the oxidation temperature is 600° C. to 700° C., and the oxidation time is 120s to 150s;

[0009] A release agent is added to the platinum crucible, and the melting and film-making process is continued in the high-frequency melting furnace to obtain a metallized pellet melt sample; the melting and film-making time is 1050s to 1240s.

[0010] Furthermore, the addition ratio of the metallized pellet sample, the calcium carbonate and the peroxide is (7-9): (5-7): (3-5).

[0011] Furthermore, the oxidation crucible is formed by pressing a lithium borate mixed reagent through a mold.

[0012] Furthermore, the lithium borate mixed reagent includes anhydrous lithium borate and anhydrous lithium metaborate in a mass ratio of 67:33.

[0013] Furthermore, the mass ratio of the metallized pellet sample to the oxidation crucible is (7-9):(100-120).

[0014] Furthermore, the inner diameter of the inlet of the oxidation crucible is 14 mm to 18 mm, the outer diameter of the bottom is 24 mm to 26 mm, and the height is 16 mm to 20 mm.

[0015] Furthermore, the release agent is ammonium iodide release agent.

[0016] Furthermore, the ratio of the amount of the release agent added to the amount of the metallized pellet sample added is (5-8):(7-9).

[0017] Furthermore, the melt-filming process includes melting, rocking and spinning to mix, standing and heating, cooling and demoulding.

[0018] Furthermore, the melting temperature is 900°C to 1000°C, and the melting time is 120s to 150s; the temperature of the rocking-spinning mixing and the static heating is both 1050°C to 1100°C, and the rocking-spinning mixing time is 450s to 500s; the rocking and spinning speeds are both 4r / min to 6r / min, and the static heating time is 30s to 40s.

[0019] Furthermore, the cooling includes self-cooling and air cooling, the self-cooling time is 150s to 220s, and the air cooling time is 180s to 220s.

[0020] The beneficial effects of this application are:

[0021] The present application can effectively improve the oxidation effect of the metallized pellets and thus greatly shorten the oxidation time by using calcium carbonate and sodium peroxide as oxidants, thereby avoiding the situation in which incompletely oxidized samples penetrate the oxidation crucible during the pre-oxidation process and thus corrode the platinum crucible. Specifically, sodium carbonate releases carbon dioxide gas during the heating process, thereby making the metallized pellet sample more loose, effectively increasing the contact area between the metallized pellet sample and the air, making the metallized pellet sample extremely easy to oxidize at high temperatures, and at the same time, combined with the strong oxidant sodium peroxide, the oxidation time of the metal element and residual carbon in the metallized pellet can be shortened to 120s to 150s. Compared with the prior art of placing the metallized pellets in a horse-boil furnace for pre-oxidation for 2 hours, the overall oxidation time has been significantly reduced.

[0022] The oxidation crucible of the present application is formed by pressing a lithium borate mixed reagent through a mold, which can effectively avoid the sample to be oxidized from contacting the platinum crucible during the oxidation stage. The lithium borate mixed reagent is actually a flux during sample melting and filming. The oxidation crucible is formed by pressing a quantitative flux through a mold, which not only avoids the sample to be oxidized from contacting the platinum crucible during the oxidation stage, but also can directly carry out heating and melting filming in the subsequent melting and filming stage without pouring the oxidized sample out of the oxidation crucible, thereby effectively improving the efficiency of the entire melting and filming. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0024] Figure 1 A physical picture of the material in the platinum crucible before oxidation is provided for this application.

[0025] Figure 2 This is the metallized pellet melt sample obtained in Example 1 of the present application.

[0026] Figure 3 This is a screenshot of the calcium oxide content detection curve in Example 1 of the present application.

[0027] Figure 4 This is a screenshot of the aluminum oxide content detection curve in Example 1 of the present application.

[0028] Figure 5 This is a screenshot of the magnesium oxide content detection curve in Example 1 of the present application.

[0029] Figure 6 This is a screenshot of the silicon oxide content detection curve in Example 1 of the present application.

[0030] Description of Figure Numbers:

[0031] 1-Platinum crucible, 2-Oxidation crucible, 3-Mixture of sodium peroxide and sodium carbonate, 4-Metalized pellet sample. DETAILED DESCRIPTION

[0032] The technical solutions of this application will be described clearly and completely below with reference to specific embodiments. Obviously, the embodiments described are only a portion of the embodiments of this application, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are intended to fall within the scope of protection of this application.

[0033] Example 1

[0034] The metallized pellets obtained by Shagang Group through solid waste resource conversion using rotary hearth furnace reduction technology are melt-cut into sheets. The melt-cutting method comprises the following steps:

[0035] 6.0000 g of mixed flux was weighed and placed in a mold and compacted to form an oxidation crucible. The mass ratio of lithium tetraborate to lithium metaborate in the mixed flux was 67:33. The inner diameter of the oxidation crucible entrance was 15 mm, the bottom diameter was 25 mm, and the height was 18 mm. 0.4000 g of the metallized pellet sample was weighed and placed in the oxidation crucible. 0.3000 g of sodium peroxide and 0.2000 g of sodium carbonate were added to the oxidation crucible and mixed. The oxidation crucible with the sample, sodium peroxide, and sodium carbonate was placed in a platinum crucible (such as Figure 1 As shown), and then put them together into a high-frequency melting furnace;

[0036] Set the melting parameters of the high-frequency melting furnace: oxidation time is 150s, oxidation temperature is 650℃, melting time is 120s, melting temperature is 950℃, swinging spin time is 460s, swinging spin temperature is 1050℃, swinging speed is 4r / min, spin speed is 4r / min, delayed heating (ie, static heating) time is 40s, self-cooling time is 150s and fan cooling time is 180s, start button to heat to 650℃ to oxidize the sample for 150s, after the sample is oxidized, add 0.3000g of ammonium iodide release agent into the platinum crucible, raise the temperature to 950℃, melt the oxidation crucible and fuse with the sample for 120s, swing and spin mix at 1050℃ for 460s, delay heating for 40s, let the liquid stand, cool and demold, and make metallized pellet melt sample. Figure 2 As shown, the surface of the metallized pellet melt sample is smooth and has no cracks.

[0037] The metallized pellet melt sample obtained by the above method was subjected to X-ray fluorescence spectrometry to determine the contents of silicon oxide, aluminum oxide, calcium oxide, magnesium oxide, manganese oxide, total iron, zinc and phosphorus in the metallized pellet sample. The working curves of each component obtained by the test are summarized in Table 1 below:

[0038] Table 1 Summary of the detection curve results of individual components in metallized pellet samples

[0039] Detection of elemental components Linear range / % Linear equations Correlation coefficient <![CDATA[SiO2]]> 2.79～60.86 w=0.4959I+0.1951 0.9999 <![CDATA[Al2O3]]> 0.54～7.84 w=0.5159I-0.03182 0.9995 CaO 0.079～61.44 w=0.8168I-0.1716 0.9999 MgO 0.27～23.27 w=1.3544I+0.02527 0.9998 MnO 0.061～5.91 w=0.04984I+0.00543 0.9996 TFe 0.78～66.87 w=0.2987I-0.1435 0.9996 Zn 0.0026～16.83 w=0.1726I-0.1403 0.9997 P 0.0064～0.584 w=0.08681I+0.00004 0.9993

[0040] Recombination Figure 3-6 The component detection curve results of calcium oxide, aluminum oxide, magnesium oxide and silicon oxide shown in the figure clearly show that the metallized pellet melt sample obtained by the method of the present application can obtain a good linear fitting effect when performing X-ray fluorescence spectrometry.

[0041] In order to verify the accuracy of the metallized pellet melt samples obtained in this application, six groups of metallized pellet melt samples (respectively designated as A, B, C, D, E, and F) were repeatedly prepared according to the method in Example 1, and X-ray fluorescence spectrometry was simultaneously performed to determine the contents of silicon oxide, aluminum oxide, calcium oxide, magnesium oxide, manganese oxide, total iron, zinc, and phosphorus in the metallized pellet samples. The test results are shown in Table 2 below. Finally, the average value, standard deviation, and relative standard deviation (RSD) of the test results of the six groups were calculated, and the final calculation results were shown in Table 3 below:

[0042] Table 2 Results of 6 repeated experimental tests

[0043]

[0044]

[0045] Table 3 Precision test results of melt film making method

[0046] Detection of elemental components average value / % Standard deviation / % Relative standard deviation RSD / % <![CDATA[SiO2]]> 4.76 0.0075 0.16 <![CDATA[Al2O3]]> 2.90 0.0089 0.31 CaO 2.58 0.0051 0.20 MgO 0.87 0.0089 1.02 MnO 0.36 0.0063 1.75 TFe 53.85 0.019 0.035 Zn 5.41 0.016 0.30 P 0.055 0.00075 1.36

[0047] The above data clearly show that the relative standard deviations (RSDs) of the six parallel tests were all ≤1.75%, with some even reaching 0.035%. This indicates that the metallized pellet melt samples prepared using this method can achieve high accuracy in testing.

[0048] Example 2

[0049] A method for melt-slicing metallized pellets, comprising the following steps:

[0050] 5.5000g of mixed flux was weighed and placed in a mold and compacted to form an oxidation crucible. The mass ratio of lithium tetraborate to lithium metaborate in the mixed flux was 67:33. The oxidation crucible had an inner diameter of 15mm at the inlet, a bottom diameter of 25mm, and a height of 18mm. 0.4500g of the metallized pellet sample was weighed and placed in the oxidation crucible. 0.3500g of sodium peroxide and 0.1500g of sodium carbonate were added to the oxidation crucible and mixed. The oxidation crucible containing the sample, sodium peroxide, and sodium carbonate was placed in a platinum crucible, and then placed together in a high-frequency melting furnace.

[0051] The melting parameters of the high-frequency melting furnace are set as follows: oxidation time is 150s, oxidation temperature is 650℃, melting time is 120s, melting temperature is 950℃, rocking spin time is 460s, rocking spin temperature is 1050℃, rocking speed is 4r / min, spin speed is 4r / min, delayed heating (i.e., static heating) time is 40s, self-cooling time is 150s, and fan cooling time is 180s. The start button is heated to 650℃ to oxidize the sample for 150s. After the sample is oxidized, 0.3000g of ammonium iodide release agent is added to the platinum crucible. The temperature is raised to 950℃, the oxidation crucible is melted and fused with the sample for 120s, rocking and spinning to mix at 1050℃ for 460s, delayed heating for 40s, the liquid is allowed to stand, cooled and demolded to make a metallized pellet melt sample.

[0052] Examples 3-6

[0053] The preparation methods of Examples 3-6 are consistent with those of Example 2, and the main difference lies in the different metallized pellet samples used, that is, Examples 2-6 respectively use metallized pellets obtained by Shagang Group in different batches of reduction for comparative experiments. The main reason is that Shagang Group's rotary hearth furnace reduction technology is a solid waste resource utilization technology, and the solid waste raw materials in different batches are uncertain. Therefore, the content of each component in the metallized pellet samples obtained from different batches is actually different and uncertain. Therefore, using multiple groups of metallized pellets from different batches for testing can be more conducive to testing the accuracy of the preparation method of this application.

[0054] Accuracy detection test

[0055] In order to verify the accuracy of the X-ray fluorescence spectrometry determination of the content of each component in the metallized pellet samples obtained in Examples 2-6 of this application, the content of each component in the metallized pellet samples used in Examples 2-6 was simultaneously tested using existing publicly available testing methods, and the test results were compared with the results of the X-ray fluorescence spectrometry determination of the metallized pellet samples obtained in Examples 2-6, as shown in Table 3 below. The existing publicly available testing methods used were: AAS for Zn content; ICP-AES for TFe, CaO, MgO, Al2O3, MnO, and P content; and gravimetric determination for SiO2 content.

[0056] Table 3 Comparison of the test results of Examples 2-6 with the test results of the prior art test method

[0057]

[0058] As can be clearly seen from the test results in Table 3 above, the X-ray fluorescence spectrometry results of the metallized pellet melt samples prepared using this method are essentially consistent with those conventionally used in the prior art, with all component detection errors below 0.05%. This demonstrates that this method is highly accurate in determining the content of each component.

[0059] The above is a detailed introduction to a method for melt-slicing metallized pellets provided in the examples of this application. Specific examples are used herein to illustrate the principles and implementation methods of this application. The description of the above examples is intended only to help understand the method and core concept of this application. At the same time, those skilled in the art will appreciate that variations in the specific implementation methods and scope of application may occur based on the concepts of this application. In summary, the contents of this specification should not be construed as limiting this application.

Claims

1. A method for melt-slicing metallized pellets, characterized in that: The steps include: The metallized pellet sample, calcium carbonate and sodium peroxide are placed in an oxidation crucible and mixed to obtain a premix; Place the oxidized crucible containing the premix into the platinum crucible; Then, the platinum crucible is placed in a high-frequency melting furnace for oxidation, the oxidation temperature is 600° C. to 700° C., and the oxidation time is 120s to 150s; A release agent is added to the platinum crucible, and the melting and film-making process is continued in the high-frequency melting furnace to obtain a metallized pellet melt sample; the melting and film-making time is 1050s to 1240s.

2. The method for melt-slicing metallized pellets according to claim 1, wherein: The addition ratio of the metallized pellet sample, the calcium carbonate and the peroxide is (7-9): (5-7): (3-5).

3. The method for melt-slicing metallized pellets according to claim 1, wherein: The oxidation crucible is formed by pressing a lithium borate mixed reagent through a mold.

4. The method for melt-slicing metallized pellets according to claim 3, wherein: The lithium borate mixed reagent includes anhydrous lithium borate and anhydrous lithium metaborate in a mass ratio of 67:

33.

5. The method for melt-slicing metallized pellets according to claim 1, wherein: The mass ratio of the metallized pellet sample to the oxidation crucible is (7-9):(100-120).

6. The method for melt-slicing metallized pellets according to claim 1, wherein: The inner diameter of the inlet of the oxidation crucible is 14 mm to 18 mm, the outer diameter of the bottom is 24 mm to 26 mm, and the height is 16 mm to 20 mm.

7. The method for melt-slicing metallized pellets according to claim 1, wherein: The release agent is ammonium iodide.

8. The method for melt-slicing metallized pellets according to claim 1, wherein: The ratio of the addition amount of the release agent to the addition amount of the metallized pellet sample is (5-8):(7-9).

9. The method for melt-slicing metallized pellets according to claim 1, wherein: The melt-slicing process includes melting, rocking and spinning to mix, standing and heating, cooling and demoulding.

10. The method for melt-slicing metallized pellets according to claim 9, wherein: The melting temperature is 900°C to 1000°C, and the melting time is 120s to 150s; the temperature of the rocking-spinning mixing and the static heating is both 1050°C to 1100°C, and the rocking-spinning mixing time is 450s to 500s; the rocking and spinning speeds are both 4r / min to 6r / min, and the static heating time is 30s to 40s.

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